Media Conversion and Encoding

When you upload a media file through your dashboard, JWP prepares the media file to be shared and streamed through a conversion and encoding process. The information below describes how and why JWP converts and encodes media files.

Media Scaling

Upscaling and downscaling allow media to conform to different viewing situations. Upscaling re-sizes lower-resolution content to fit a broader range of screen sizes, while downscaling allows content from one source to play on different displays in their native resolution.

Because upscaling tends to result in a loss of resolution or picture quality, JWP will only downscale an output rendition. For example, if an uploaded video has a 720p resolution, JWP will not create a 1080p rendition. The highest output resolution will be 720p.



Media Output Formats

JWP creates the following encoded renditions in MP4 containers by default:

Resolution Profile Level B-frames Enabled Audio Codec
1080p H.264 HighĀ  4.0 Yes AAC audio
720p H.264 MainĀ  4.1 Yes AAC audio
540p H.264 MainĀ  3.1 Yes AAC audio
360p H.264 MainĀ  3.0 Yes AAC audio
270p H.264 BaselineĀ  3.0 No AAC audio
180p H.264 BaselineĀ  2.1 No AAC audio

JWP also creates the following adaptive streaming outputs:

Properties without DRM enabled Properties with DRM enabled
HLS: MPEG-DASH:
  • H.264 video
  • AAC audio
  • AES-128 Common Encryption
  • Widevine and PlayReady DRM variants
HLS:

* requires enablement by JWP Support representative



Bitrate Caps

JWP uses capped CRF encoding to create media renditions and determine the bitrate cap for each rendition. A proprietary algorithm determines the optimal peak bitrate for the content. This approach makes the most efficient use of available bits in the rendition.

This bitrate cap prevents the encoded media stream from exceeding a peak bitrate. If the content is not complex (such as media with little fast movement or fine detail), the output may render under the cap, but never over.

For example, an encoded rendition with a bitrate cap of 1,000 Kbps might have an effective bitrate of 600 Kbps but never 1,100 Kbps.



Audio Channels

By default, JWP matches the number of audio channels in the upload. If an uploaded video has 5.1 channel audio, JWP will create both stereo and 5.1 renditions.